Colby Recreational Trails System

Garrison Beck ’13 and Larissa Lee ’13
ES212: Introduction to GIS and Remote Sensing
Environmental Studies Program, Colby College

Abstract

Our map displays the Colby College trail system, along with campus buildings, pathways, an orthophoto background, rivers, ponds and streams. We created a digital elevation model based on contour line data. From there, we developed different levels of difficulty for the trails based on ranges in elevation. We created a 3-D model and exported video fly-through clips.

Introduction

Colby has many trails on its property. The goal of this project was to update the current trail map to display current and proposed paths through the campus woods and arboretum that students, faculty, community members, and visitors use. We created a more user friendly version to inform outdoor adventurers of the distance of each path, as well as its difficulty based on the difference in elevation. Map users will be able to view our video fly-through of the trails online.

Methods

We used ArcGIS 9.3 to create our maps. We acquired the background imagery (2009) from the Maine office of GIS NAIP orthophotos. We used the trail data from Knight and Fereday (2010). The Colby basemap and contour lines were taken from Colby Physical Plant Department Data. River, stream, and pond data were from the Maine Office of GIS.  We used land cover data from the Maine Office of GIS. Previous trial data was edited to ensure continuity and updated where necessary. Trails were color coded based on current Colby identifications and also on difficulty. We defined difficulty as the range in elevation for each trail: less than 50 meters = easy; between 50 and 150 meters = medium; over 150 meters = difficult. We used contour lines to calculate degree slope for the Colby campus.  We used land cover data to give users a reference for the surrounding environment. We drew the new trail as a feature by approximating the path proposed by Physical Plant, but has not yet been constructed and may not reflect the future trail. Using ArcScene, we created this 3-Dimensional model of the Colby area and recorded videos of a simulated fly-through of the trail network. This trail data will be available for use in Google Earth as an interactive map of the area.

Results

Trail distances on campus range from 0.21 miles to 4.16 miles. Elevation on the trails ranges from 111.1 meters to 392.8 meters. These differences affect trail difficulty (Table 1 and Figure 1). Degree slope on campus ranges from 0˚ to 62.47˚ (Figure 2). Trails remain mainly in the mixed forest land cover (Figure 3).

Table 1. Difficulty of Colby Trails based on range in elevation

Trails	Distance	Elevation Ranges	Difficulty
Yellow	0.51	129.0 - 210.5	Medium
Red	0.37	113.9 - 148.6	Easy
Green	0.91	149.4 - 240.3	Medium
Blue	0.31	157.1 - 200.2	Easy
Purple	0.21	135.1 - 162.5	Easy
White	0.3	111.1 - 157.3	Easy
PPD	0.91	140.6 - 251.4	Medium
Runnels	4.16	186.5 - 392.8	Difficult
New	1.1	202.5 - 381.7	Difficult

Figure 1. Difficulty of Colby Trails based on range in elevation

Figure 2. Slope of the Colby Campus in degrees

Figure 3. Different land cover types on the Colby Campus

Conclusion: We have developed three versions of Colby campus trail maps. These include a 2-Dimensional map depicting trail classifications and difficulties, a 3-Dimensional map depicting elevation, and an interactive map to be used with Google Earth. The classification, difficulty, and interactive maps will be made available for those interested in the Colby recreational trail system.

Acknowledgements: We would like to thank Philip Nyhus and Manny Gimond for all their help and support in finding, analyzing, and presenting data to create a useful map.

Data Sources:

Maine Office of GIS provided: land cover data, river data, stream data, pond data, and NAIP orthophotos 2009

Knight and Fereday, 2010 Student Research Project Spatial Analysis of Colby College provided: campus trails data

Colby College Physical Plant Department provided: Information for new trail, campus roads, buildings, and sidewalks